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* Fix the following issues:
1. HashMap non-thread-safe issus
2. Fix the same problem in pr621, but use a better implementation

Add the following functions:
1. There is now a language cache inside getLanguage to prepare for different languages corresponding to different time zones where the accounts in the server are located

* add /language command,each account has their own Locate

Change target perm from target.perm to x.perm.others

fix #635

Optimize multilingualism (using variables)

Add multilingual support

Limit the avatar level given by "/givechar" command.
If avatar level >90, the game will freeze if open the character interface.

Signed-off-by: Jaida Wu <mlgmxyysd@meowcat.org>